A white IUD on a yellow platform

How Long Does It Take For An IUD To Start Working?


Call me "paranoid," but I once messaged my gynecologist on her personal Facebook to ask her to reassure me that I wasn't pregnant. 

Yeah. I went there.

Before you make any assumptions that I'm a total psycho who stalks her doctors on their private social media accounts, allow me to explain myself.

It was Saturday morning, and the guy I had been seeing for a while spent a majority of Friday night in my bedroom. After he left, I was lying down, reminiscing the wild time we had (use your imagination), and then a traumatic question popped into my head: "Is my IUD working yet?"


About four days before my panicked, post-sex Saturday, I got an IUD (Intra-Uterine Device). When I woke up that morning and realized how soon it had been since the IUD was shoved into my uterus, I began to question whether or not I should've waited longer to put it to use.

I thought, "Oh god, should I have waited a few more days? Do I need to go buy Plan B? Can you even take Plan B when you have an IUD? What'll happen if I get pregnant with this thing inside me?! Dammit, Amanda."

Considering the fact that it was the weekend and my gynecologist's office was closed, I checked the next best source for much-needed IUD answers: Google. I typed "How long do you need to wait to have unprotected sex after getting an IUD?", and the answers I found scared the shit out of me.

There were tons of women claiming you should "wait a month" or "a few weeks" so you could let your IUD do it's thang and get adjusted to your bod — and at that point, I was borderline hyperventilating because it had only been four days. FOUR.

So, I did what any logical person would do and searched for my gynecologist on Facebook so I could slide into her DMs and ask her about my uterus. I guess my stalking skills are up to par, because I found her almost instantly and hopped into FB messenger.

I told her I had unprotected sex a few days after getting an IUD, and asked if it was too soon. My doctor's response was short and sweet.

Amanda Fama

Halle-freakin'-lujah... I was protected.

After experiencing such uncertainty about my IUD, I couldn't help but wonder if other women are facing the same question I did.

If you're one of those women asking yourself if your IUD is working yet, have no fear — I have answers for you.

When IUDs start working

Before we get into detail about the different types of IUDs and how long each takes to start working, keep in mind there are two types of IUDs: hormonal and non-hormonal.

A hormonal IUD, such as the Mirena, Skyla, Liletta, and Kyleena, releases small amounts of a progestin hormone called levonorgestrel into the uterus and will prevent pregnancy up to five years (depending on which device you choose). It can be removed at any time.

A non-hormonal IUD, such as the ParaGard, releases copper inside your uterus and will prevent pregnancy for up to 10 years. It can also be removed at any time.

In order to find out exactly how long it takes for each IUD to start working, I reached out to Prudence Hall, MD of The Hall Center in Santa Monica, CA.

(Don't worry — I didn't message her on Facebook. I emailed her like normal, less frantic human.)

Dr. Hall told Elite Daily,

The IUDs start working right away — the only thing you want to make sure is that you're not pregnant. It's best to put an IUD in on your period. This gives you a two-week period before you're actually going to ovulate. So say the first day of your period is day one, you ovulate day 12 to 14.

Dr. Hall was referring to hormonal IUDs. Women who choose them should have the devices inserted during their period for immediate effectiveness.

If you didn't get your hormonal IUD inserted during the beginning of your menstrual cycle (aka your period), you should use backup contraception for seven days after insertion, according to research from the American College of Obstetricians and Gynecologists (ACOG).

But if you go from one hormonal birth control straight to the IUD, then you're in the clear (that's what I did).

The ACOG bulletin says the copper IUD works immediately, no matter what time of the month you have it inserted.

So, basically, the copper IUD is the only non-hormonal IUD that works immediately upon insertion, unless you have the hormonal IUD inserted during your period.

However, Planned Parenthood says the IUD is still the most reliable birth control method out there, regardless of which one you choose. They're over 99 percent effective, which means only 1 out of 100 women who use them will get pregnant each year.

This, my friends, leads me to my next point.

How you could actually get pregnant with an IUD in

So, what happens if you do get pregnant while you have an IUD? The scary answer involves ectopic pregnancies.

Ectopic pregnancy is an extremely rare condition where the fertilized egg attaches itself somewhere other than the uterus, like the fallopian tube. If this happens, there is no other option but to end the pregnancy.

Dr. Hall came to rescue and said,

They [IUDs] do not create ectopic pregnancies, but they don't stop them. They only stop a pregnancy that's in the uterus, so if there's a pregnancy inside a tube, the IUD will not stop that pregnancy. So, what kind of pregnancies do we see on the IUD? Ectopic pregnancies.

Because the IUD prevents an egg from implanting inside the uterus, the egg might implant itself outside of it — which would result in this condition.


Like I said before, an IUD is over 99 percent effective, and if you use it correctly, chances are extremely high that you'll be totally fine.